<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>bootstrap布局2</title>
    <link rel="stylesheet" href="../css/bootstrap.css">
</head>
<style>
    .container{
        border: dashed 1px red;
    }
    .show{
        border: solid 1px blue;
    }
</style>
<body>
    <div class="container">
        <div class="row">
            <div class="show col-sm-4 col-lg-6 col-xl-12">第一列</div>
            <div class="w-100"></div>
            <div class="show col-sm-4 col-lg-6 col-xl-12">第二列</div>
            <div class="show col-sm-4 col-lg-6 col-xl-12">第三列</div>
        </div>
    </div>
    <br/>
<script src="../js/jquery.min.js"></script>
<script src="../js/bootstrap.js"></script>
<script>
    $(function(){
        console.log("jquery入口函数启动")
    })
</script>
</body>
</html>